Piston pump



Feb. 2, 1965 N. LAING 3,

PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 1 ITZVQTLZLOF- By N Law-71g Feb. 2, 1965 N. LAING 3,158,050

PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 2 In ea-211v, By LzilLny #11232 AZZya Feb. 2, 1965 N. LAING 3,168,050

PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 3 I In V WZ OF N- Lezz'vzg Feb. 2, 1965 N. LAING 3,168,050

PISTON PUMP Filed Jan. 5, 1962 17/ Sheets-.-She,et; 4K-v ya I a 1 #2/ FIG. 3. I 9

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PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 7 N- Lain N. LAlNG 3,168,050-

PISTON PUMP Feb. 2, 1965 Filed Jan. 5, 1962 17 Sheets-Sheet 8 w Mia J07 1W4 2 7 My Feb. 2, 1965 N. LAING 3,16 50 PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 10 if? J 2 64 jdfi 070W if? F G 7 7a l I v LL/- By Mm gi zm/ N. LAING PISTON PUMP Feb. 2, 1965 17 Sheets-Sheet 11 Filed Jan. 5, 1962 Irz vevz To /V- Lzc ng Atz N. LAING PISTON PUMP Feb. 2, 1965 17 Sheets-Sheet 12 Filed Jan. 5, 1962 Inve-nfor Lain; M M44;

N. LAING PISTON PUMP Feb. 2, 1965 17 Sheets-Sheet 14 Filed Jan. 5, 1962 N. LAING PISTON PUMP Feb. 2, 1965 17 Sheets-Sheet 15 Filed Jan. 5, 1962 Feb. 2, 1965 N. LAING 3,168,050

PISTON PUMP Filed Jan. 5, 1962 17 Sheets-Sheet 17 0 {W F/G.23.

United States Patent ()fi ice 3,lii8,5 Patented Feb. 2, 1965 3,16%,tld PISTON PUMP Nikolaus Laing, Rosenbergstrasse 24a, Stuttgart, Germany Filed Jan. 5, 1962, Ser. No. 164,552 Claims priority, application Germany .lan. 5, 7361 19 Claims. (Ci. 193 161) This invention relates to piston pumps.

The invention provides a piston pump comprising a rotary guide system and a cooperating rotary pumping system; said pumping system including a cylinder block, a pump body mounting said cylinder block for rotation about a first axis and providing in association therewith intake and delivery chambers extending about said rotary piston each over a major portion of a 180 arc centred on said first axis, and a reciprocating piston mounted in said cylinder block for movement to and fro along a path which is fixed with respect to said cylinder block and transverse to said axis: said guide system including a guide member which is rotatable about a second axis spaced from the first axis, and means coupling said systems whereby in operation to reciprocate said reciprocating piston along said path so as to draw fluid from the intake chamber and discharge it into the delivery chamber in each revolution of the cylinder block.

One drawback of known types of piston pumps in use with liquid is their limited suction head. Suction head is determined in part by atmospheric pressure, vapour pressure of the liquid, and the resistance of the pipe leading to the intake of the pump; nothing can be done about these factors. However further major factors determining the suction head of a pump are the length of intake passages wherein liquid is accelerated, the speed of operation and certain dimensions of the pump. The lengh of the intake passages cannot in known piston pumps be reduced indefinitely because of the need for a valve controlling intake.

The present invention avoids the need for a valve controlling intake and so enables a better suction head to be obtained than with a pump of known type under similar conditions. It also enables the pump to be dimensioned for further improvement of the suction head.

In one preferred embodiment of the invention, the guide member of the guiding system may be a guide member piston spaced axially from the cylinder block and the coupling means may be a reciprocating slide mounted in the guide member for movement to and fro along a path which is fixed with respect to the guide member and transverse to the second axis, and a coupler rigidly coupling the reciprocating members. This enables the guide system to function also as a pumping system, by the provision of intake and discharge chambers in association also with the second rotary piston.

If it is not desired to use the guiding system for pumping, the same disposition as mentioned in the preceding paragraph may be used, but without provision of intake and discharge chambers for the guide member, which becomes merely a conveninet device to carry the reciprocating slide. In the case this slide may be a simple rectangular-section slide: this has constructional advantages that will be explained later.

In a pump according to the invention the pumping sy tem may have several cylinder blocks, as may also the guiding system have several guide members, these cylinder blocks and guide members being arranged in spaced relation along the axes. The diiferent pumping sections may be connected in series or in parallel.

The pump according to the invention is readily controllable to vary the output at constant speed: this can be done by reducing the stroke of the reciprocating pistons of the pumping systems by reducing the spacing between first and second axes, or by displacing the intake and delivery chambers relative to those axes so that the reciprocating pistons discharge somewhat to the intake chamber.

The invention has two further valuable aspects: thus according to one aspect it provides a piston pump for liquids having at least three pumping sections and an intermediate container, said section including a stage delivering liquid to said container, a further stage taking liquid from the container and delivering it towards an outlet, and a leakage section taking liquid which has leaked from other parts of the pump and delivering it to the container. There is therefore no need to provide pistonor shaft-sealing means, because leakage is recirculated; this in turn reduces the power consumption of the pump for a given output and makes it easier to construct.

According to the second further aspect the invention provides a piston pump for liquids comprising at least two stages (called first and second stages), an intermediate container between the first and second stages, an intake from which (directly or indirectly) the first stage takes liquid, an outlet towards which (directly or indirectly) the second stage delivers liquid, and a pressure-relief valve connected between the outlet and the container and set to a predetermined pressure whereby to deliver liquid from the outlet to the container when the outlet pressure exeeds the predetermined pressure. There is also, preferably, a pressure relief valve between the container and the intake.

The features of the last two paragraphs can conveniently be combined: a further preferred feature is a capillary tube leading into a leakage-collecting zone from a high point in the container to remove air which may be pumped thereto, the capillary tube presenting a small resistance to air but a large resistance to liquid.

The features of the last three paragraphs are advantageously combined with those mentioned earlier in a triple section pump, having a first rotary system acting as a guide system and a second rotary system which exhibits a cylinder block having three sections and wherein are guided three reciprocating pistons. The first rotor section of said triple section pump is a main pumping section. The medium to be conveyed is pumped into an intermediate tank from this section. From the latter it is conveyed into the delivery pipe by a second pumping section which acts as a dosing or metering pump section. The third pumping section serves as a leakage pump. The liquid pumped leaks out between the reciprocating pistons and their bores; this leakage is channelled to the suction pipe of said third pumping section and is returned directly into the intermediate tank.

Various embodiments of the invention will now be described by way of example with reference to the ac companying diagrammatic drawings, in which:

FIGS. 1a to 1d are diagrammatic plan views of a piston pump according to the invention illustrating the two rotary systems thereof in different positions;

FIGS. 1e and 1] are diagrams illustrating the motion of a coupler forming part of the pump of FIGS. 1a to 1d;

FIGS. 2a to 2d are views similar to FIGS. 1a to 1d of a modified form of pump;

FIG. 3 is a partially sectioned perspective illustration of a further form of piston pump showing the relative disposition of the two rotary systems;

FIG. 4- is a sectional perspective view of another piston pump according to the invention, comprising two rotary systems, one system with guide members and one system with cylinder blocks, the pumping system inciuding three reciprocating pistons;

FIG. 5 is a perspective illustration of parts of yet another pump wherein the drive is provided through a coupler and not through a rotary piston;

FIG. 6 is a perspective view showing parts of a composite pump according to the invention made up of two component pumps each with two rotary systems acting as pumping systems; the guide members and cylinder blocks and the casing (shown in part only) are depicted rawn apart;

FIG. 7 is a perspective view of a coupler coupling two reciprocating pistons, as may be employed in pumps according to the invention;

FIGS. 7a, 7b and 70 show in partial perspective different forms of couplers;

' FIG. 8 is a section through a pump according to the invention in which the throughput may be varied;

FIG. 9 is a sectional view of a pump which shows another arrangement for the continuous variation of the throughput;

FIG. 10 is a section along the line XX in FIG. 9;

FIGS. 11:: and 11b are partial perspective views which show dispositions for the sealing and lubrication of a guide member or cylinder block in a pump according to the invention;

FIG. 12 is a sectioned perspective illustration which diagramamtically shows parts of a pump according to the invention having three pump pistons;

FIG. 13 is a longitudinal section of a practical form of construction of the pump diagrammatically illustrated in FIG. 12;

FIG. 14 is a sectional view along line XIVXIV in FIG. 13;

FIG. 15 is a section through a pressure relief valve forming part of the pump illustrated in FIGS. 13 and 14 (this section is taken in a plane different from the section planes of FIGS. 13 and 14);

FIG. 16 is a diagram showing the relative positions of the rotary systems in the pump of FIGS. 13 to 15 and showing also section lines XIII-XIII and XIVXIV (the eccentricity of the centres of axes of the guide members and cylinder blocks is shown exaggerated);

FIG. 17 is a flow chart for the pump system illustrated in FIGS. 12 to 16;

FIG. 18 is a partially sectioned exploded perspective view of a further form of pump wherein the positive coupling of two rotary systems is provided by means of fiat sliders;

FIG. 19 is a section through a pump incorporating a rotary system as illustrated in FIG. 18; v

FIGS. 20a to 20d show different forms of reciprocating pistons for use in pumps according to the invention, FIGS. 20a and 200! being perspective views of two different pistons and FIGS. 20b and 20c being longitudinal section and plan of a further form of piston;

FIG. 21 is a longitudinal section of a further practical embodiment of a pump according to the invention;

FIG. 22 is a section along line XXIXXI in FIG. 23;

FIG. 23 is a section along line XXIIL-XXIII in FIG. 21;

FIG. 24 is a section along line XXIV-XXIV in FIG. 21;

FIG. 25 is a section along line XXV-XXV in FIG. 21, and

FIG. 26 shows in perspective view a first rotary system and a reciprocating piston of a second rotary system, forming part of the pump illustrated in FIGS. 21 to 25.

The operation of one preferred embodiment of the invention will first be described with reference to the diagrams of FIGURES 1a to 1 it is intended that this description should make it easier to understand the more detailed embodiments which are described later.

FIGURES 1a to 1d show a pump with its working parts in four difierent positions. The pump comprises two rotary systems comprising a cylinder block 1 and guide member 11 respectively formed with a diametral throughbore 5, and guide track 15 respectively containing reciprocating members in the form of a piston 2, and a guide element or slide 12 respectively which are slidable to and fro along the bore and track respectively. FIG- URES la to 1d each show two superimposed sections, one through the central planes of the cylinder block 1 and guide member 11 at right angles to the axes of rotation thereof. The pump includes a pump body but for clarity of illustration this body is illustrated only by the wall parts 3, 3 and 13 and 13' a pair for each rotary system, which divide intake and outlet chambers from each other.

One rotary system is indicated by full lines, whereas the other system is drawn in dotted lines. The cylinder block 1 of the first system has the form of a hollow cylinder rotating about the axis and being driven in the direction of the arrow 4.

The second rotary system is shown in dotted lines and is disposed beneath or above the first system; the guide member 11 of the second system rotates about the axis of rotation 10 and is driven in the direction of the arrow 14.

The reciprocating members 2, 12 are rigidly interconnected by means of a coupler 6 in the form of a square section rod received in square holes in the reciprocating pistons; thus the piston and slide perform a positively coupled motion wherein the reciprocating member of the one system possesses only one translatory degree of freedom or mobility relative to the other system, enabling it to perform a reciprocating motion in the bore of the cylinder block or guide member within which it is guided. In the example illustrated, the reciprocating members are. arranged at relative to each other. Though this angle of 90 will commonly be preferred in principle however the reciprocating members may be disposed at other angles to one another.

Assuming that FIGURE 1a shows the parts of the pump in a datum position, FIGURES 1b, 1c and 1d show these parts displaced by 45, 90 and respectively from the datum. The 180 displaced position corresponds to that of FIGURE 1a, while the positions wherein the parts are displaced by 225, 270 and 315 correspond to FIG- URES 1b, 1c and 1d respectively.

FIGURES 1e and 1 illustrate the motion of the coupler: FIGURE 1e shows the geometry of the arrangement and FIGURE 1 is a vector diagram. The coupler axis C moves about the imaginary axis D halfway between the axes of rotation 0 and 10 of the two systems, which turn at identical angular velocity W The coupler axis C moves on a circular cylinder having a diameter equal to the distance between the axes 0, 10, and its motion may be interpreted as a superimposed motion about the axes of rotation 0 and 10. The velocities of the motions about the axis of rotation 0 and 10, v and 1 may accordingly be added vectorially, in order to describe the velocity V of the coupler about the axis D. As will be understood from the drawing, this velocity V is constant and the motion of the coupler is therefore uniform.

It is possible, therefore, to operate the pump by driving the coupler with its axis travelling on a circular cylinder of diameter e: the coupler must however be so disposed as to be rotatable about its axis C. It will however generally be preferred, for constructional considerations, to supply the drive to one of the two rotary systems, e.g. either the cylinder block 1 or guide member 11. As will be seen from FIGURES 1a to 1 the perpendicular distance between the two axes of rotation 0, 10 corresponds to half the length of a stroke of the pistons and slide 12. A motion through 360 of the central axis of the coupler then corresponds to a rotation of both systems through 180.

The coupler 6 is in each instance disposed centrally in both the piston 2 and slide 12.

In the diagramatically illustrated pump of FIGURES 1a to 1d both rotary systems may be utilised as pumping systems; one system, the first system for example, may however act solely as a guide system and the second system alone may act as a pumping system.

As apparent from FIGURES 1a to 1d, when both systems are utilised as pumping systems, the delivery side for the first system including the cylinder block 1 is located on the right-hand side (as seen in the drawing) of the plane of symmetry passing through the housing parts 5 and 3', and the suction side is accordingly located to the left thereof. The reverse applies for the second system having the guide member 11; this system delivers towards the left-hand side as shown in the drawing.

One of the main advantages of the pump described lies in the fact that, in the or each rotary system a single reciprocating member exerts suction on one side as well as pressure on the other side, through an angular range of almost 180. When one extremity of a reciprocating memberat the end of the pressure stroke-reaches the dead centre at which the extremity of the reciprocating member comes closest to the periphery of the corresponding cylinder block or guide member, it is carried along through a very short distance past the housing portion 3 or 13' separating the suction side from the delivery side, and then immediately starts on the suction stroke, whereas the other extremity of the same reciprocating member simultaneously starts on the delivery stroke again. Valves as in known piston pumps, or valve control gear, are thereby rendered superfluous.

The cylinder block 1, and guide member 11 are formed with a central cylindrical opening dimensioned so that firstly the reciprocating piston 2 and slide 12 are adequately guided during their entire reciprocating motion, secondly that a sufliciently pressure-tight seal is assured relative to the inner spaces of the hollow cylinders, and thirdly that the required space is available for the travel of the coupler 6.

FIGURE 2 illustrates a disposition similar to FIGURE 1. The difference between these dispositions resides in that the guide member 11 drawn in dotted lines possesses a greater diameter than the cylinder block indicated by full lines. The same reference numerals as in FIGURE 1 have therefore been utilised throughout, and no further description will be required.

The advantage of the FIGURE 2 pump is that the housing which is required to guide the cylinder block 1 and guide member 11 may easily be produced by fitting an excentric ring serving as a guide for the block 1 into the top and/ or bottom of a simple cylindrical casing co-operating with the guide member 11 having the greater diameter.

FIGURE 3 shows a perspective illustration of a further form of pump according to the invention, having a first rotary system comprising two shafts 21 and 21 mounted in fixed bearings (not illustrated) so as to be rotatable about the same axis of rotation 20; one or other of these shafts may be driven by means (not shown) or both shafts may be driven synchronously. These two shafts 21 and 21' correspond in principle to the guide member 11 illustrated in FIGURES 1 and 2, but function merely to guide a pair of slides 22 and 22' movable along transverse slots 25 and 25 formed in the opposed extremities of the shafts 21 and 21. The second rotary system comprises a cylinder block 31 rtoatable about the axis 30; the block 31 is shown in perspective section so as more clearly to illustrate a diametrical bore 35 wherein a reciprocating piston 32 is slidably mounted. The slides 22 and 22 are rigidly coupled to the reciprocating piston 32 by means of a coupler 26. The housing 33 wherein rotates the cylinder block 31 is indicated only diagramatioally, and the required inlet and outlet chambers in the housing are not illustrated.

6 shown in FIGURES 1 and 2, and the piston 32 is caused to travel back and forth in the bore 35 as shown in FIG- URES 1 and 2.

The FIGURE 3 pump may be modified by replacing the block 31 by a cylinder block having several bores and disposed in a housing constructed accordingly. These bores then contain a corresponding number of reciprocating pistons which are all interconnected rigidly by means of the coupler. A pump of this type can be utilised as a multi-section pump, as will hereinafter be set forth in greater detail.

The guide system illustrated in FIGURE 3 comprises two partial systems disposed on either side of the pumping system along the direction of the axes of rotation. A two-part type of construction of this kind is necessary, in order to locate the coupler 26 symmetrically, so that a torque may be transmitted to the cylinder block 31 without the occurrence of forces which could cause the pistons to seize in their bores.

FIGURE 4 is a perspective section of a pump following the principles of FIGURE 2 wherein both rotary systems exhibit reciprocating pistons and slides guided respectively in a cylinder block and guide member, the section line being taken along a line corresponding to the line IV-IV of FIGURE 20. The first of the two rotary systems comprises a pair of similar spaced guide members 41, 41 which correspond to guide member 11 indicated in dotted outline in FIGURE 20 and have an axis of rotation 49 which corresponds to the axis 10 in FIGURE 2. The second rotary system comprises a cylinder block 51 located between the guide members 41, 41' and having an axis 56 which corresponds to the axis of rotation 0 of the rotary piston 1 in FIGURE 2c. Drive is supplied to the guide member 41 through a plate 46 attached thereto by means of bolts 47 and carrying a stub shaft 48 which may be coupled to a motor for example by a universal joint. Alternatively a direct drive or belt or other drive could be used. The cylinder block 51 possesses three bores 55a, 55b and 550, whereof the axes lie in one plane (the section plane as illustrated in FIGURE 4). Pistons 52a, 52b, 520 are slidably mounted in the bores and rigidly connected by a coupler 49 with slides 42, 42' slidable in parallel tracks in the guide members 41, 41'. (The coupler 49 and the reciprocating pistons 52a, 52b and 52c are sectioned. The cylinder block 51 is sectioned through its central plane, whereas the guide member 41 is sectioned along a lane which is parallel and excentric to its central plane, as apparent from FIGURE 20. Beyond its section plane, the reciprocating slide 42) is shown in dotted lines in order clearly to show its position relative to the reciprocating pistons 52a, 52b, 52c.)

In the position shown in FIGURE 4, and as also apparent from FIGURE 20, the central axis of the coupler as coincides with the axis of rotation 50 of the cylinder block 51.

When the plate 46 is driven in the direction of the arrow 44 the guide member 41 turns in the bore 56 of the housing 57, which is indicated in dotted lines. (Suction and delivery chambers of the housing 57 are not shown in the drawing.) As a consequence of the rigid connectic-n between the reciprocating slide 42 and the reciproeating pistons 52a, 52b, 520 by the coupler 49, a rotation of the guide member 41 causes a rotation of the cylinder block 51 in the bore 58 of the housing 57 which is excentric to the bore 56.

The central axis of the coupler 4% rotates about an axis disposed between the two axes of rotation and 56, as already described in detail in connection with FIG- URES 1 and 2.

The FIGURE 4 pump has a first rotary system which may be utilised both as a guide system and as a pumping system. The three reciprocating pistons 52a, 52b, 520 of the second rotary system oscillate together and provide a separate three part pumping system and these parts may be connected in parallel or in series as desired, by 

1. A PISTON PUMPING COMPRISING A PUMP BODY, A CYLINDER BLOCK MOUNTED FOR ROTATION WITHIN THE PUMP BODY ABOUT AN AXIS AND DEFINING A PLURALITY OF PARALLEL BORES EXTENDING TRANSVERSELY TO SAID AXIS, A PISTON RECIPROCABLY MOUNTED IN EACH OF SAID BORES, THE PUMP BODY DEFINING WITH THE CYLINDER BLOCK, AN INTAKE CHAMBER AND A DELIVERY CHAMBER FOR EACH OF SAID BORES, BOTH CHAMBERS EXTENDING OVER THE MAJOR PORTION OF A 180* ARC CENTERED ON SAID AXIS, GUIDE MEMBERS ONE AT EITHER END OF THE CYLINDER BLOCK AND MOUNTED FOR ROTATION WITHIN THE PUMP BODY ABOUT A SECOND AXIS PARALLEL TO AND SPACED FROM THE FIRST-MENTIONED AXIS, SAID GUIDE MEMBERS PROVIDING PARALLEL TRACKS EXTEND- 